Using your circular saw, cut a 20 x 27cm board out of the wooden countertop.
Then attach a hole saw to your drill and make a hole with a diameter of 5cm. This hole should be placed at the middle of kitchen plate, closer to the short end of the board (see the drawing below).
Then saw the board through the middle with a circular saw.
Sand to smoothen the cut edges.
Taking one half of the board, try to insert the long side into the EKBY BJÄRNUM bracket. If the board is too thick for the bracket, get a grinder and make the plate a bit thinner at the end, so that it fits the bracket snugly.
Lastly, attach the EKBY BJÄRNUM brackets to the wall using appropriate wall fixings. Use a level to get the brackets on straight.
But tough luck on finding a good set of STOLMEN telescoping poles (though there are still some available on eBay), so why not try three bikes in a row on an IVAR frame instead? With a coat of paint, it could look pretty striking.